Piston expander



Aug. 16, 1938.

A. W. GRAY PISTON EXPANDER Filed July 1, 1936 2 Sheets-Sheet l Inventor Aitorneys 7 I l I A. w. GRAY 2,127,169

PISTON EXPANDER Filed July 1, 193a Attorneys 2 Sheets-Sheet 2 Patented Aug. 16, 1938 UNITED STATES PISTON EXPANDER Arthur W. Gray, Ellensburg, Wash. Application July 1, 1936, Serial No. 88,490

3 Claims.

This invention is a device to facilitate the expanding of a piston. The general practice at the present time is to expand or enlarge a piston by striking the same with a hammer, but this i manner of so expanding a piston has proved unsatisfactory for the reason that it is impossible to obtain a uniform expansion of the piston due to the fact that on account of the length of the skirt it is practically impossible to place the hammer inwardly of the piston as far as the head thereof as is necessary to obtain a uniform expansion of the piston.

In accordance with the present invention an electrically operated hammer is provided and will be found particularly adapted for use in expanding pistons, together with efiicient means for supporting the pistons in operative position to the hammer.

The invention together with its objects and advantages will be best understood from a study of the following description taken in connection with the accompanying drawings wherein:-

Figure 1 is a top plan View of the device.

Figures 2 and 4 are sectional views taken substantially on the lines 2--2 and 4-4 respectively of Figure 1.

Figure 3 is a side elevational view of the device.

Figure 5 is a perspective View of an anvil.

Figure 6 is a wiring diagram.

Referring to the drawings by reference numerals it will be seen that in the preferred embodiment thereof the device comprises a base block 5 having a raised portion 6 that extends for substantially one-half the length of the block to 35 one end of the latter.

Provided in the raised portion 6 of the block is a transverse groove 1 in which fits a channel 8 the side walls of which are provided with oppositely extending lateral flange or plate extensions 9 that rest on the raised portion 6 at opposite sides of the slot 1.

Disposed transversely of the plates 9 and channel 8 are slides I 0 which are provided at their respective .opposite end edges with inturned flange portions l I that engage the adjacent edges of the plate or flange extensions 9 for slidably retaining the slides ID in position for adjustment toward or away from one another.

Formed integral with the plate extensions ID are ribs l2 that have inclined portions 13 to en gage the periphery of the skirt of the piston resting on the plate [0.

Disposed transversely of the channel 8 at about the longitudinal median of the block 6 is 55 an anvil l4 that is provided with an apertured depending lug l5 that extends down into the channel 8 as shown in Figure 4. At its respective opposite ends the anvil i4 is provided with open ings 16 for the accommodation of rivets or other suitable fastening means whereby said ends of 5 the anvil are secured to the plate or flange extension 9.

For adjusting the plates relative to one another and to the anvil Hi there is accommodated within the channel 8 an adjusting screw ll hav- 10 ing oppositely threaded end portions l8 which are threadedly engaged in the threaded apertures of lugs 19 that extend into the channel 8 and are formed integral with or otherwise secured to the plates Ml as shown in Figure 4. Obvious- 1y by turning the screw I1 plates III are moved toward or away from one another and relative to the anvil M as found desirable. By a proper adjustment of the plates I!) the piston to be expanded is properly centered over the anvil I4. 20/

Suitably secured to the stem end of the block 5 adjacent the raised portion 6 is a plate 20 on which are mounted a pair of magnets 2|, 22 that are wired together as at 23. One of the magnets is connected through the medium of a wire 24 with a terminal post 25 suitably provided on the block 5 and which post is in turn suitably connected with one side of a source of electrical energy as, for example, a battery or the like (not shown).

Rising from the plate 20 is a standard 26 provided at its upper edge with a flange 21 that is supported from the block 5 through the medium of suitable bolt and nut means 28.

The flange 21 is connected with the standard 26 through the medium of an off-set portion 29 to which is bolted or otherwise secured as at 30 the flanges of a bracket plate 31. Bolted to the plate 3| as at 32 is an arm 33 of-conductive material and this arm is provided with a contact 34.

Also bolted to the flange 21 as at 35 is an angular spring arm 36 provided with a contact 31 complemental to the contact 34.

As clearly shown in the wiring diagram of Figure 6 the magnet 22 is connected in circuit with the contact 31 through the medium of a wire 38 while the contact 34 is wired in the circuit through the medium of a wire 39 that is connected to a second terminal post Ml which in turn is connected to the opposite side of the battery or other suitable source of electrical supply.

A hammer is provided and includes a shank M which at one end is bolted or otherwise secured as at 42 to an intermediate portion of the spring 5 -:a constant repetition of this cycle of arm 36. At its opposite or free end the shank 4| of the hammer is provided with a head 43 that is disposed over the anvil M for striking the skirt of the piston.

Adjacent its bolted end the shank 4| of the hammer has suitably secured thereto an armature plate 44 disposed in operative position to the magnets 2| to be attracted thereby when the magnets are energized to cause the hammer 4| to move downwardly for striking the head 43 thereof against the skirt of the piston with sufficient force to obtain the results desired.

In connection with the above it will be noted that the resilient arm 36 is normally flexed upwardly to engage contact 37 with contact 34. With the contacts thus engaged the circuit will be completed through the magnets 2| and 22.

Upon energization of said magnets armature 44- will be attracted thereby to cause the hammer 4| to move downwardly into forcible contact with the skirt of the piston supported on the plates I0. Obviously as the armature 44 moves downwardly under influence of the magnets 2|, 22 resilient arm 36 will be flexed downwardly for ,;moving the contact 31 out of engagement with interrupting the circuit When the circuit is thus 32 will flex upwardly to Thus by operation hammer 4| is caused to have a vibratory action for imparting a series of blows to the skirt of the piston as found desirable in expanding the piston so that the same will'have a proper fit when placed within its power cylinder.

It is thought that a clear understanding of the construction, utility and advantages of an invention of thischaracter will'be had without a more detailed description.

Having thus described the invention what is claimed as new is:-

the contact 34 thus through the magnets. interrupted spring arm again re-engage contacts 3'! and 34.

1. In a machine for reshaping pistons, a base plate having at its center a channel-shaped portion, an anvil superimposed on said base plate and having a lug depending in the channel, an adjusting screw disposed in said channel and swivelly mounted for rotation on said lug, a pair of adapter units superimposed and slidably mounted on said base plate, said unit bridging the channel and having portions depending into said channel and operatively joined to the adjusting screw to facilitate movement toward and from the anvil to accommodate piston heads of varying diameters.

2. In a machine for reshaping pistons, a base plate having at its center a channel-shaped portion, an anvil superimposed on said base plate and having a lug depending in the channel, an adjusting screw disposed in said channel and swivelly mounted for rotation on said lug, a pair of adapter units superimposed and slidably mounted on said base plate, said adapter units being provided with inclined portions elevated above said base plate and converging toward each other to serve as conforming rests for the shell of said piston head. I

3. In a machine for reshaping pistons, a base plate, upstanding portions on said base forming a transversely extending. channel, an anvil having a flat working surface on said base plate, a lug on said-anvil extending intosaid channel, an adjusting screw disposed in said. channel and mounted for rotation in saidxlug, ap-air of holder units on opposite sides ofsaid. anvil, said. units being threadedly connected to said adjusting screw for movement towards and away from said anvil, andsaid units being provided with diverging portions elevated above said anvil whereby different sized pistons may be held on said anvil to subject the piston to azhammering action to reshape the same.

ARTHUR W. GRAY. 

